A laminated glass including two glass plates bonded to each other with an interlayer film for a laminated glass containing a thermoplastic resin in between is widely used for glass windows of automobiles, aircraft, or buildings, for example.
An interlayer film for a laminated glass may include only one resin layer or may be a laminate including two or more resin layers. Including a first resin layer and a second resin layer which have different properties from each other as two or more resin layers, an interlayer film for a laminated glass can have various properties hardly achieved by a monolayer structure.
Patent Literature 1, for example, discloses a three-layer sound insulation interlayer film for a laminated glass which includes a sound insulation layer and two protective layers interposing the sound insulation layer therebetween. The interlayer film for a laminated glass disclosed in Patent Literature 1 includes a sound insulation layer containing a polyvinyl acetal resin that is highly compatible with a plasticizer and a large amount of a plasticizer to exhibit excellent sound insulation properties. The protective layers prevent bleed-out of a large amount of the plasticizer contained in the sound insulation layer to prevent lowering of adhesiveness between the interlayer film and glass plates.
Patent Literature 2 discloses an interlayer film for a laminated glass which includes a belt-like colored layer along the upper portion of a laminated glass for a vehicle. Such a colored layer prevents sunlight from coming into sight of the driver, providing high anti-glare properties.
However, in the case of disposing a colored layer in a multilayered interlayer film for a laminated glass, linear color unevenness can occur in the colored portion which causes poor appearance. Such poor appearance is especially noticeable in cases where a colored layer is disposed in an interlayer film for a laminated glass excellent in sound insulation properties such as an interlayer film disclosed in Patent Literature 1.